National Review reports here that after putting Scott Walker through a politically motivated John Doe investigation, Democrats in Wisconsin have turned their attention to conservative activist groups in the state. The investigation into Walker found nothing illegal related to his campaign, but it was used to smear the governor to no avail before his successful recall election run.

But while the investigation went away, the investigators did not. The same prosecutors who went after Walker prior to his recall election have now returned, launching another John Doe investigation into whether conservative groups may have unlawfully coordinated to help Walker win the recall.

According to a piece in the Wall Street Journal over the weekend, subpoenas for these groups have been issued over the past month:

Copies of two subpoenas we’ve seen demand “all memoranda, email . . . correspondence, and communications” both internally and between the subpoena target and some 29 conservative groups, including Wisconsin and national nonprofits, political vendors and party committees. The groups include the League of American Voters, Wisconsin Family Action, Wisconsin Manufacturers & Commerce, Americans for Prosperity — Wisconsin, American Crossroads, the Republican Governors Association, Friends of Scott Walker and the Republican Party of Wisconsin.

One subpoena also demands “all records of income received, including fundraising information and the identity of persons contributing to the corporation.” In other words, tell us who your donors are.

These subpoenas seek to accomplish what campaign-finance reformers have failed at so miserably over the past decade: to expose the names of people who support conservative causes but contribute to third-party groups anonymously. In many cases, conservative donors want to remain anonymous in order to prevent the type of intimidation tactics virulent liberals will use against them. (As the WSJ notes, during Walker’s recall, many businesses that supported Walker were “outed,” and thus subject to boycotts by union sympathizers.)

It appears that investigators are looking into whether these groups provided Walker’s campaign with a “benefit” that should have been reported on Walker’s finance reports, and whether these benefits were improperly coordinated with Walker’s reelection effort. But what constitutes a “benefit” is certainly vague. Any number of actions can affect an election, and few of them ever show up on an official finance report.